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At least 217 records · Page 12Linked to original sources
PubMed2004

Radio frequency ablation of small renal tumors:: intermediate results.

PURPOSE: With evolving radio frequency technology, the clinical application of radio frequency ablation (RFA) has been actively investigated in the treatment for small renal tumors. We present our intermediate patient outcomes after RFA. MATERIALS AND METHODS: Since January 2001, 17 patients with a total of 24 hereditary renal tumors ranging from 1.2 to 2.85 cm were treated with RFA using the 200 W Cool-tip RF System (Radionics, Burlington, Massachusetts) under laparoscopic (9) or percutaneous (8) guidance and had a minimum 1-year followup. A percutaneous approach was considered unsuitable if kidney tumors were contiguous to bowel, ureter or large vessels. Treatment eligibility criteria included an average tumor diameter of less than 3.0 cm, tumor growth during 1 year and solid appearance with contrast enhancement (HU change greater than 20) on computerized tomography (CT). Postoperative followup consisted of CT with and without intravenous contrast, and renal function assessment at regular intervals. RESULTS: Median patient age was 38 years (range 20 to 51). At a median followup of 385 days (range 342 to 691), median tumor or thermal lesion diameter decreased from 2.26 to 1.62 cm (p = 0.0013), and only 1 lesion (4%), which was located centrally near the hilum, exhibited contrast enhancement (HU change greater than 10) on CT at 12 months. Of the 15 renal tumors ablated laparoscopically, 13 were in direct contact with the bowel and 2 were abutting the ureter, necessitating mobilization before RFA. Laparoscopic ultrasound was used to guide radio frequency electrode placement and monitor the ablation process in these cases. Operative time and intraoperative blood loss (mean +/- standard mean of error) were 243 +/- 29 minutes and 67 +/- 9 cc, respectively. In 1 patient whose ureter was adherent to the tumor a ureteropelvic junction obstruction developed after laparoscopic RFA, requiring open repair. CONCLUSIONS: At the minimum 1-year followup 23 of 24 ablated tumors lacked contrast uptake on CT, meeting our radiographic criteria of successful RFA treatment. RFA treatment of small renal tumors using the Radionics system appears to result in superior treatment outcomes compared to those of earlier series with lower radio frequency power generators. A high wattage generator might attain more consistent energy deposition with subsequent cell death in the targeted tissue due to less convective heat loss.

Adult↗
PubMedDate not supplied

Accuracy of computerized tomographic evaluation of canine radio-ulnar incongruence in vitro.

OBJECTIVE: To evaluate the accuracy of linear measurements obtained from computer tomography (CT) images of staged radio-ulnar incongruence in a canine cadaver forelimb model. STUDY DESIGN: CT evaluation of induced progressive radio-ulnar incongruence in canine cadaveric forelimbs. SAMPLE POPULATION: Eight cadaveric canine left forelimbs. PROCEDURE: A type 2 external skeletal fixator (ESF) with linear motors was attached to the radius in 8 cadaveric left canine forelimbs. Contiguous incremental and helical CT images of the proximal radio-ulnar articulation were acquired in the transverse, sagittal and dorsal planes. The radius was shortened by 1, 2, and 4 mm increments and scanning protocols were repeated at each increment. Digital caliper and CT image analysis measured the progressive change in distance between 2 marking spheres and the epiphyseal bone surfaces of the radio-ulnar articulation. Statistical analysis of measurements from incremental and helical CT acquisitions, and direct and reformatted images were compared with inter-sphere distance using Pearson product moment correlation coefficients. RESULTS: The reformatted incremental acquisition series at the mid-coronoid in the oblique plane had the highest correlation coefficient (r-value) at 0.908. The mid-coronoid in the dorsal plane had the second highest r-value (0.856). The coronoid incisure in the sagittal plane had an r-value of 0.826. The reformatted incremental acquisition series at the coronoid incisure in the oblique plane had the lowest r-value, 0.592. CONCLUSION: Measurement of radioulnar incongruence may be best performed using reformatted incremental acquisition CT in the mid-coronoid region in an oblique plane. CLINICAL RELEVANCE: Use of the technique reported in this study may enable determination of the association, if any, between radioulnar incongruence and developmental diseases of the canine elbow.

Animals↗
PubMed1996

The physiological and behavioral effects of radio music on singly housed baboons.

The response of four singly caged baboons to radio music was measured using behavioral and physiological indices. Heart rate and blood pressure, measured through a tether system, as well as behavior, were recorded during a two-week period in which radio music was available in half of the samples. The behavior of the subjects, as well as their blood pressure, did not vary in relation to radio music. Heart rate was significantly lower when the radio was on.

Animals↗
PubMed2002

Particle accelerators in the hot spots of radio galaxy 3C 445, imaged with the VLT.

Hot spots (HSs) are regions of enhanced radio emission produced by supersonic jets at the tip of the radio lobes of powerful radio sources. Obtained with the Very Large Telescope (VLT), images of the HSs in the radio galaxy 3C 445 show bright knots embedded in diffuse optical emission distributed along the post-shock region created by the impact of the jet into the intergalactic medium. The observations reported here confirm that relativistic electrons are accelerated by Fermi-I acceleration processes in HSs. Furthermore, both the diffuse emission tracing the rims of the front shock and the multiple knots demonstrate the presence of additional continuous re-acceleration processes of electrons (Fermi-II).

Journal Article↗
PubMed2003

Orbital motion in the radio galaxy 3C 66B: evidence for a supermassive black hole binary.

Supermassive black hole binaries may exist in the centers of active galactic nuclei such as quasars and radio galaxies, and mergers between galaxies may result in the formation of supermassive binaries during the course of galactic evolution. Using the very-long-baseline interferometer, we imaged the radio galaxy 3C 66B at radio frequencies and found that the unresolved radio core of 3C 66B shows well-defined elliptical motions with a period of 1.05 +/- 0.03 years, which provides a direct detection of a supermassive black hole binary.

Journal Article↗
PubMed2003

Enhanced optical emission during Crab giant radio pulses.

We detected a correlation between optical and giant radio pulse emission from the Crab pulsar. Optical pulses coincident with the giant radio pulses were on average 3% brighter than those coincident with normal radio pulses. Combined with the lack of any other pulse profile changes, this result indicates that both the giant radio pulses and the increased optical emission are linked to an increase in the electron-positron plasma density.

Journal Article↗
PubMed2004

Radio and plasma wave observations at Saturn from Cassini's approach and first orbit.

We report data from the Cassini radio and plasma wave instrument during the approach and first orbit at Saturn. During the approach, radio emissions from Saturn showed that the radio rotation period is now 10 hours 45 minutes 45 +/- 36 seconds, about 6 minutes longer than measured by Voyager in 1980 to 1981. In addition, many intense impulsive radio signals were detected from Saturn lightning during the approach and first orbit. Some of these have been linked to storm systems observed by the Cassini imaging instrument. Within the magnetosphere, whistler-mode auroral hiss emissions were observed near the rings, suggesting that a strong electrodynamic interaction is occurring in or near the rings.

Journal Article↗
PubMed1993

Radioisotope determination of regional colonic transit in severe constipation: comparison with radio opaque markers.

Radio-opaque markers have a well established role in distinguishing between patients with normal and those with slow intestinal transit, but in the latter group their accuracy in defining the region of delay has not been established. To study regional colonic transit accurately the transit of a radioisotope labelled meal was determined and findings were compared with those of simultaneously ingested radio-opaque markers. Twelve healthy controls (mean age 33 years) and 12 severely constipated women (mean age 36 years, bowel frequency < once per week) were studied On day 1, a meal containing 10 MBq 111In bound to 0.7 mm resin microspheres was ingested. Subjects also ingested a set of radiologically distinguishable markers on three successive days. Abdominal scans were obtained three times daily for 7 days. Abdominal radiographs were obtained after 72 or 96 hours and again at 144 or 168 hours. Eight 'regions of interest' were created--one for the small bowel, six for the colon, and one for excreted stool. The constipated patients all showed colonic transit outside the normal range, with a variable site of delay demonstrated by time activity curves for each region. To provide a different measure of the effectiveness of colonic transport, the movement of the 'centre of mass' for the radioisotope and for the markers was then determined. The radioisotope and radiopaque marker methods gave similar results. At all times between 24 and 144 hours there was no significant difference for the position of the centre of mass between the radio-opaque and marker methods. At all times, however, the mean difference between the markers and the radioisotopes was positive, indicating that the center of mass of the markers was always head of that of the radioisotope. The mean difference between the methods was never greater than one region of interest, and ranged from 12 to 72% of one region of interest in the colon. The difference between these two methods could reach up to two colonic segments in certain patients at one time. Radioisotope ingestion provides accurate information about the transit through individual colonic regions because of the possibility of frequent observations and the clear delineation of the entire colon. Although these features were not obtained with radio-opaque markers, they are suitable as a screening test for the presence and pattern of colonic delay.

Adult↗
PubMed2001

Essential techniques for successful radio-frequency thermal ablation of malignant hepatic tumors.

Radio-frequency thermal ablation is one of the most promising minimally invasive techniques for the treatment of nonresectable hepatic tumors. Essential technical tips to successful radio-frequency ablation therapy were collected from five international experts. They were organized into five categories: understanding the mechanisms and principles of radio-frequency ablation, modulation of tissue physiologic characteristics to increase tumor destruction, strategies of overlapping ablations, strategies to improve ablation according to tumor location, and imaging strategies after ablation to ensure adequate therapy. Established factors for optimal ablation, as well as emerging technical tips, are addressed with illustrations in each section. These essential tips will be very helpful for physicians performing radio-frequency ablation of hepatic tumors.

Catheter Ablation↗
PubMed1994

Qualitative mapping of cerebral blood flow and functional localization with echo-planar MR imaging and signal targeting with alternating radio frequency.

PURPOSE: To create qualitative maps of cerebral blood flow (CBF) with the EPISTAR (echo-planar imaging and signal targeting with alternating radio frequency) technique. MATERIALS AND METHODS: The EPISTAR technique was performed in a pig model of hypercapnia and then tested in 26 volunteers by using various paradigms for cortical activation. Echo-planar images were acquired with and without use of a radio-frequency inversion pulse applied to inflowing arterial spins. A qualitative map of CBF was then created by subtracting the image obtained without the radio-frequency pulse from that obtained with the radio-frequency pulse. RESULTS: Progressively more distal portions of the tagged vessels were seen as the inflow time was lengthened until cortical enhancement was seen for inflow times of approximately 1 second or longer. Signal intensity increases from rest to sensorimotor activation ranged from 13% to 193%. CBF changes in the motor strip, primary visual cortex, and the motor area for eye movements were well localized to the cortical gray matter ribbon. CONCLUSION: The EPISTAR technique is a rapid, noninvasive means for creating qualitative maps of CBF.

Animals↗
PubMed1985

Anatomical studies on the geometry and stability of the distal radio ulnar joint.

In fresh-frozen amputated- and cadaver arm specimens the anatomy and stability of the distal radio ulnar joint were investigated. The articulating surface of the sigmoid notch of the radius and the corresponding surface of the ulnar head facing the sigmoid notch were studied in transverse cryo sections. In each specimen the radius of the curvature of the sigmoid notch was 4-7 mm larger than that of the ulnar head and consequently pronation and supination are combined rotation-sliding movement in the distal radio ulnar joint. The radio ulnar ligament consists of a dorsal and a volar fibrous part, broadly attached to the distal rim of the sigmoid notch and converging towards the fovea of the ulnar head. The cartilaginous disc is centrally located between these fibrous strands. In neutral position the articulating surface of the sigmoid notch is optimally covering the articulating surface of the ulnar head. This contact area is gradually diminished during pronation-supination until only a marginal contact remains at the end of each movement. The distal radius is kept stable in pronation by the volar part and in supination by the dorsal part of the radio ulnar ligament.

Adult↗
PubMed2003

Radio frequency "sutureless" fistulotomy- a new way of treating fistula in anus.

AIM: To explore the effect of the classical lay open technique or fistulotomy with the radio frequency surgical device in the treatment of fistula in anus. METHODS: In our study, the conventional 'lay open' technique, or 'fistulotomy' was performed by employing the radio frequency surgical device as an alternative to the traditional knife and scissors. In a span of 18 months starting from July 1999 to December 2000, 210 cases with fistula in anus of varied types were operated in our nursing home exclusively applying the radio frequency device. RESULTS: The results of the study were not only encouraging but also were satisfactory. A follow up of the operated patients with radio frequency surgery over a period of 15 months, i.e. from December 2000 to March 2002 was summarized as below: (a) average time taken by the patient to resume routine - 7 days; (b) none of the patient had any interference with the continence; (c) the wounds were found healed within an average time of 47 days; (d) delayed wound healing was noticed only in 7 patients; (e) recurrence/ failure rate was reduced to as low as 1.5 percent. CONCLUSION: This technique has been found superior to the conventional fistulotomy in the sense that the time taken for the whole procedure is reduced to almost half, chances of bleeding are reduced to a minimum and the use of suture material is dispensed with. The procedure can safely be called a "Sutureless fistulotomy".

Adult↗
PubMed2002

Assessment of therapeutic response in hepatocellular carcinoma treated with percutaneous radio frequency ablation: comparison of multiphase helical computed tomography and power Doppler ultrasonography with a microbubble contrast agent.

OBJECTIVE: To compare the results of multiphase helical computed tomography and power Doppler ultrasonography with a microbubble contrast agent in the assessment of the therapeutic response to radio frequency ablation in hepatocellular carcinoma. METHODS: In 66 patients with 73 nodular hepatocellular carcinomas ranging from 1.0 to 4.0 cm (mean, 2.6 cm) in diameter, contrast-enhanced power Doppler ultrasonography was performed after intravenous bolus injection of a galactose-based microbubble contrast agent before and after radio frequency ablation. The results of the studies were compared with the findings of follow-up 3-phase helical computed tomography. All patients were regularly followed up with computed tomography for more than 1 year (range, 13-19 months). RESULTS: In 8 (11%) of 73 hepatocellular carcinomas, immediate follow-up computed tomography obtained within 2 hours after radio frequency ablation showed focal enhancing portions within the treated lesions, suggesting residual non-necrotic tumors. All 8 of these tumors had intratumoral flow signals on contrast-enhanced power Doppler ultrasonography. The diagnostic agreement between computed tomography and contrast-enhanced power Doppler ultrasonography was achieved in 100%. Among the remaining 65 hepatocellular carcinomas with the absence of residual tumors at both immediate follow-up computed tomography and contrast-enhanced power Doppler ultrasonography, subsequent follow-up computed tomography showed local regrowth at the margins of 10 lesions (15%). CONCLUSIONS: The results of contrast-enhanced power Doppler ultrasonography closely correlated with those of immediate follow-up computed tomography for detecting residual tumors in hepatocellular carcinomas treated with radio frequency ablation. Both techniques, however, showed a limitation in detecting small or microscopic residual tumors and in predicting local regrowth in the treated lesions.

Adult↗
PubMed2005

Evaluation using contrast-enhanced harmonic gray scale sonography after radio frequency ablation of small hepatocellular carcinoma: sonographic-histopathologic correlation.

OBJECTIVE: To evaluate the usefulness of contrast-enhanced harmonic wideband gray scale sonographic images obtained after radio frequency-induced coagulation necrosis, we compared the morphologic and histopathologic characteristics of the ablated tumors with sonographic images of the tumors. METHODS: Forty-eight patients with 72 hepatocellular carcinomas with a maximal diameter of 3 cm or less were treated percutaneously using radio frequency ablation. Six treated tumors in 4 patients were resected 1 month after ablation; the remaining 66 treated tumors were evaluated by a biopsy procedure performed with an 18-gauge fine needle 1 month after ablation. The excised tumors and biopsy specimens were then examined by histopathologic methods, and the findings were compared with those obtained on contrast-enhanced harmonic wideband gray scale sonography. Hematoxylin-eosin-stained specimens were inconclusive as to whether cellular viability remained; therefore, cell viability was determined by a positive result after histochemical (lactate dehydrogenase and nicotinamide adenine dinucleotide phosphate-diaphorase) staining. RESULTS: Contrast-enhanced harmonic wideband gray scale sonography after radio frequency ablation showed residual tumor enhancement in 5 (6.9%) of the 72 tumors; the histopathologic results for these 5 tumors were also positive for tumor residue. The remaining 67 tumors (93.1%) did not show any residual tumor enhancement when examined by sonography; however, only 66 tumors did not reveal tumor residue when examined histopathologically. Contrast-enhanced harmonic wideband sonographic imaging provided results that were comparable with histopathologic findings, the criterion standard for diagnosis; the sensitivity and specificity of the sonographic images for the detection of residual tumor tissue in ablated tumors were 83.3% (5 of 6) and 100% (66 of 66), respectively. CONCLUSIONS: Contrast-enhanced harmonic wideband gray scale sonography is a potentially useful technique for evaluating the therapeutic effects of radio frequency ablation on hepatocellular carcinoma.

Aged↗
PubMed1999

Supportive use of amifostine in patients with head and neck tumors undergoing radio-chemotherapy. Is it possible to limit the duration of the application of amifostine?

BACKGROUND: Amifostine is a new cancer-supporting agent to protect normal tissue in patients receiving radio-chemotherapy. The main question of our study is whether the application of amifostine can be limited on the duration of chemotherapy in patients with advanced head and neck tumors undergoing radio-chemotherapy. PATIENTS AND METHODS: In a randomized study 14 patients were treated with amifostine (500 mg, day 1 to 5 and 29 to 33) during concurrent radio-chemotherapy with carboplatin (70 mg/m2, day 1 to 5 and 29 to 33), 14 patients were treated without amifostine. The analyzed parameters were dermatitis, mucositis, skin temperature, white blood and platelet count, creatinine and scintigram of salivary glands. Median survival of the amifostine group was 19 months, of the control group 10 months. RESULTS: There were no relevant differences in all analyzed parameters between both arms of the study. CONCLUSION: Our form of amifostine application is probably not able to obtain a relevant reduction of the toxicity of radio-chemotherapy.

Adolescent↗
PubMed1999

Relation between endoscopic ultrasound evaluation and survival of patients with inoperable thoracic squamous cell carcinoma of the oesophagus treated by combined radio- and chemotherapy.

AIM: Purpose of this study was to assess prognostic value of endoscopic ultrasound in patients with inoperable squamous cell carcinoma of oesophagus treated by radio-chemotherapy. PATIENTS AND METHODS: Between January 1993 and March 1996, 89 patients (77 males and 12 females, mean age 60.3 years) with squamous cell carcinoma of the oesophagus were treated exclusively by radio-chemotherapy consisting of 3 courses of chemotherapy using 5FU-Cis-platyl and 3 courses of radiation therapy (3 x 15 Gy). Endoscopy and endoscopic ultrasound (Pentax FG 32 UA) were performed before beginning treatment and two weeks after last cycle of radio-chemotherapy. Classical criteria for endoscopic ultrasound lymph node metastases were used after irradiation; response was considered as complete only if endoscopic ultrasound indicated that integrity of oesophageal wall was fully restored. RESULTS: Complete endoscopic ultrasound assessment was achieved in 73 cases (84.9%). Tumours were classified as T1N1 in 1 case, T2N1 in 7, T3N0 in 4, T3N1 in 24, T4N0 in 1 and T4N1 in 49. For patients with a non-invasive tumour (usT1 or T2), malignancy of lymph nodes was proved by endoscopic ultrasound guided biopsy. Eighty-two patients presented one or more suspicious lymph nodes. Metastatic lymph nodes were located in posterior mediastinum in 43 cases, at distant sites in 27 (laterotracheal in 16 and coeliac in 11) and in 16 lymph nodes were located simultaneously in mediastinum and at distant sites. Median overall survival in these 89 patients was 16 months. There was no significant difference in median survival between patients in stage T3 and T4. Conversely, there was a significant difference between patients with more or less than 4 metastatic lymph nodes (9 vs 36 months, respectively, p = 0.005). Site of lymph node metastasis was also a prognostic factor with better survival in patients presenting mediastinal nodes than those presenting coeliac nodes (30 vs 9 months, respectively, p < 0.0001). Median survival was also significantly better in patients considered as having achieved a complete response by both gastroduodenal fibrescopy and endoscopic ultrasound than in those considered to have a complete response by gastroduodenal fibrescopy but not by endoscopic ultrasound (49 vs 10 months). Conversely, there was no difference in survival in function of treatment response assessment by thoracic chemotherapy-scan. CONCLUSION: Endoscopic ultrasound findings regarding number and site of suspicious lymph nodes and degree of treatment response are significant prognostic factors in patients with squamous cell carcinoma of oesophagus treated exclusively by radio-chemotherapy.

Adult↗
PubMed1995

Efficacy of standard ten millicurie dose of radio-iodine in management of autonomously functioning toxic thyroid nodules.

Therapeutic effect of radio-iodine treatment on thyroid patients with autonomously functioning toxic thyroid nodule was evaluated. Fifty one patients were given a standard dose of 10 mci of radioiodine (I-131) and were followed up for 2-3 years. The failure rate (relapse after 10 mci of radioiodine) of this regime was 10%. It was found that the nodules less than or equal to 3 cms. in size were completely cured after a dose of 10 mic. of radio-iodine therapy, over a follow up period of next 6 months. Patients having nodules larger than 3 cms. relapsed after first dose of 10 mci of radio-iodine, but were cured completely after the second dose of 10 mci of radio-iodine therapy. Tri-iodothyronine (T3) and thyroxine (T4) values were both found to be high before giving treatment in all the cases. Only one case developed hypothyroidism after radioiodine therapy.

Female↗
PubMed1998

[Clinical and experimental study on Fuzheng Baozhen Decoction enhancing effect of radio- and chemotherapy for malignant tumors].

OBJECTIVE: To study on Fuzheng Baozhen Decoction (FZBZD) enhancing effect of radio- and chemotherapy for malignant tumors. METHODS: One hundred and Seventeen cases of malignant tumors treated with chemotherapy or/and radiotherapy, 55 cases treated together with FZBZD (group A), comparing with 30 cases treated with radio- and chemotherapy plus Zhenqi Fuzheng Granules (group B) and 32 cases radio- and chemotherapy alone (group C). Mechanism of FZBZD enhancing effect of chemotherapy on transplanted human lung adenocarcinoma (SPC-A-1) and sarcoma (S180) bearing mice was conducted. RESULTS: Effective rates (CR + PR) of group A, B, C were 63.6%, 43.3%, 37.5% respectively, that of group A was the best (P < 0.05). The survival quality of life was improved best in group A (P < 0.05). After being treated, the level of the peripheral blood (WBC, Hb, PLT) of group A was the highest (P < 0.05); CD3, CD4, NK activity, interleukin-2 were also improved significantly in group A (P < 0.01). Animal experiment showed that FZBZD could improve chemotherapy effect of inhibitory action on tumor growth (P < 0.01), increase cAMP/cGMP ratio (P < 0.01) by adding cAMP level in cancer tissue, and enhance of G0/G1 phase cells and decrease S phase cells. CONCLUSIONS: FZBZD inhibited tumor growth and enhanced the effect of radio- and chemotherapy by improving immune and hematopoietic function, cAMP/cGMP ratio and stagnating tumor cells in G0/G1 phase.

Aged↗